Caster



April 13 192 0 E. A. H ELLER Filed Oct. 13, 1924 V El.

Patented Apr. 13, 1926.

UNITED I .jlj580g245 BATE-NT; Q I-CL,

"av-Weep 1 or emote new.

. a iieati n filedjQctober-lS, 1924. Serial no. 143,289.

To aZZ whom it may concern:

Be it known that L EDWARD Allnennn, a citizen'ot the UnitedStatesyresiding at Detroit, in the county of Wayne and State of ldichigan have invented anew and use;- ful Improvement in a Caster, of which the following is a specification. My invention relates to a new and usefuliinprovement in a caster andhas for its object the provision of a caster having ball bearings adapted for receiving the thrust deliveired to the-caster, said ball bearlngs being positioned in non-planar sets, the upper set of balls being adaptedto receive 7 the horizontal thrustyand in, this way, at taming a greater height -1I1 the mount ng of the caster, so as to permit a more sensitive SWiVelliDg than when the balls are placed on the same horizontal plane.

Another object of the inventionis'to place oneset of balls directly aroundand lying against the vertical pintle of.- the caster and so positioned as to engage the side walls of a cup in which they are placed, thus relieving to the. maximum the frict on in'cident to the swivelling of the caster and consequently,

increasing the efliciency of the caster.

Anothei"*-result froinf placing; the, row jolt.

ballsa-round the vertical pintl'e in a cup is the use of a lesser amount of balls, Which also results in a'sier. swivelling'and affords an econoniical structure iii-manufacture;

-Another ob ect of the invent on IS the provision of a washer embracing thepintle for retaining-"the pintlefengaging' balls in the cup'a'nd forafiording means for adjusting the" position of the washer 'relativelyto the balls, thus presenting a 'means for'reta'ining 'the washer in tontact with the-balls,

as the various parts becoine'worn, thus preventing the balls from dropp ng or being otherwise removed from their normal position.

Another object of the invention is to provide a vertieal pintle with a fiat square head which permits the same tobefseated or anchored in the recess of the underside ofxa yoke, thus permitting a generous portion of thehead to extend downwardly, aifording a reinforcement for the yoke by means of the head, itself. This reinfo1'cen ent'is directed to that portion of the housing which is subjected to the greatest resulting 'i'roin side" thrust;

Another. result of havin q the head so conr d 1-5:. the. absqri tieebt hock? h. i

delivered on the uppeiflpoint of the pintle whenithe same is being swelled. to prevent a removal lof the .Washer tromthe pintle, the washer,lieiiig firstset on the ipintle and the pintle swelled or partly riveted to retain the washer in position.

Another. result of having'a square head mountedin a recess is the prevention of a rotation of the pintle relatively tothe yoke, so that the hole in theyoke is not Worn the'pintl'e which extends therethrough. as would bethe case upon a relative rotation of tbeseparts. l I p 'Another object of the invention is. the 7 provision of a caster having a pintle adapted supportingthe rotatable wheel and PIOJ- vided with a slottor engaging a rib on the downwardly projecting portions of the y ing. j I

Another object ofthe invention is the pro.- vision of a recess in the top of the yoke for Y receiving lubricants which maybe. depositedthe 'tions and arrangements of parts hereinafter described-and cla med.

lhefinvention will be best understood from a reference to the 7 accompanying drawings which Lforn' a part of this specification and in which, L i d f fFig. l a view of the invention showing part inelevation and a part in central vertical sectionalview,

FigwQ is a tecti'onal view stantial'ly line Q2 of Fig. 1,

Fig-. 3 is a fragmentary side elevational view of the lower portion of the invention; Fig. 41. is" a fragmentary side elevational view of the lower portion of the invention 100 from theopposite side. I 7 r j The caster comprises anattaching'plate 7, which-"is provided With suitable openings 8 for receiving attaching ineans i'or attaching the attachment plate to the body. upon 9 taken on sub which it is to be used. The caster set forth in the invention is adapted for the general use to which cast'ers'are customarily applied.

-'lheattaching plate is provided with an the-same face is a circular boss 10,ythe

so as to preventv the pintle from rotatspace between the periphery of the boss 10 and the flange 9 providing a raceway for balls 11, which are positioned therein. A portion 12 of the undersurface of the boss 10 is bevelled to lie in parallel relation with an inclined surface 13 of asupporting yoke which is used with the attaching plate, aspace separating the inclined surface 12 and the inclined surface 13. The main body of the yoke 1d is in spaced relation to the boss 10, to provides space 15. The attaching plate 7 is provided with a recess 16 leading from which cent-rally thereof is a passageway 17. The yoke 161 is provided, on its undersurface, with a secondary recess 18. A pintle 19 is projectedthrough an opening formed in the upper wall of the yoke 14-. and through the passageway 17 into the recess 16. The pintle 19 affords a snug or pressfit with the yoke 14;. This pintle is provided with an interiorly threaded bore in which is threaded a stem 20, which is provided on its upper end with a head 21 having a downwardly projecting flange 22, which engages the upper surface of a washer 23 positioned on the pintle 19 in embracing relation, said pintle 19 being swelled or slightly riveted over the washer 23, so as to retain the same in assembled relation on the pintle 19. Ball bearings 24 are positioned in the recess 16, so as to engage the base of the recess, the inner walls of the recess and the undersurface of the washer 23. It will be noted that the balls 2 1 enagainst the inner surface of the recess 16, which is formed circular and against the periphery of the pintle, so that there is no play between the pintle and the side walls of the recess. It is also to be noted that the washer 23 is of less diameter than the. diameter of the recess 16,'so that no engagement is had between the side walls of the recess and the periphery of the washer. It is also to be noted that the balls 21 are of less diameter than the balls 11, the difference in the balls permitting a more compact structure in manufacture. It is also to be noted that the lower surface of the balls 21 are tangent to the same plane as the upper surface of the balls 11. It is also to be noted that the balls 11 are arranged in a larger circle than the balls 21. This arrangement is such that the side thrust delivered to the caster is directed longitudinally of the pintle 19 in the maximum degree. This results from the hearing points which are pressing as the side thrust will be delivered to the balls 11 and to the balls 24c. The arrangement of having the;e balls in separate planes transforms the pintle 19 when side thrust is delivered thereto into a double fulcrurned lever, whereas, were the balls 11 and 24 to afford bearing points on the same plane, a greater tively to the standard.

standard 27 1s a rib 33 wh ch terminates at.

leverage would result, inasmuch as the pintle 19 would then become a single fulcrumed lever, the point of fulcrum being at that point where the balls 2 1 engage.

The structure is a durable one for receiving side thrusts. By arranging the balls in this relative position, a reduction of friction is brought about and the swivelling of the housing relatively to the attaching plate becomes easier.

The head 25, which is provided on the pintle 19, is square so as to fit snugly in the recess 18, thus preventing a relative rotation of the pintle 19 and theyoke 14:. By maintaining the pintle in fixed relation to the yoke 1%, the wear incident to a rotation of the pintle in the yoke is eliminated, thus affording a greater life to the yoke itself. It will be noted'that the head 25 extends over a large portion of the upper. wall of the yoke 14: and in this way, the yoke is reinforced, so that a side thrust transmitted through the pintle 19 to the yoke 1 1 is delivered to, the housing over a large area through tl e head 25.

Projecting downwardly from the yoke 14, are standards 26 and 27, each provided with an opening in aiinement with the opening in the opposite standard for the reception of an axle 28 upon which is rotatably mounted the caster wheel 29. Formed on the outer face of the standard 26 is a rib 30 having the lower end 31 thereof formed senLi-circular and adapted to project so as to engage in a groove 32 formed in the head 22 of the axle 28, to prevent rotation of the axle rela- Eormed on the its lower end 3% in a wedge-shaped formation, so as to spread the opposite ends of a cotterpin 35, which is projected through the axle 28. It is thus seen that the axle is prevented from rotating and that the ribs 30 and 33, in addition to serving the functions already mentioned, also serve to-reinforce these downwardly projecting standards, to strengthen them for performing the various functions required of them.

By providing the space 15, it is evident that lubrication positioned within this space, after use will be retained and there is no passage of escape for the same, inasmuch as the pintle 19 is al pressiit with the yoke 14:. Thus it will be apparent that the moving parts will always have lubrication present inasmuch as the lubrication will be permitted to creep upwardly of the axle, so as to lubricate the balls 2st and to move outwardly to lubricate the balls 11.

lVhen the balls 24-. become worn, or the engagement between the balls and the washer 23 becomes loose, an adjustment of these parts relatiihly to each other may be had by threading the stem 29 in the shaft 19, thus bringing the engagement legs 22 and 22 downwardly in the recess '16, so as to press the washer firmly against the balls 24. In order to effect this, the lower end 36of the stem is formed square, or such a formation as to permit the holding of the stem by a wrench, in order to effect a turning of the same in the pintle'19. It will be apparent that the pintle I19 cannot turn on account of the engagement of the head 1n the recess 18 A suitable lock nut 37 is positioned on the-lower end ofthe stem 20.

While I have illustrated and described the preferred form of structure, I do not wish to limitmyself to the precise form of structure shown, but desire'to avail myself of such variations and modifications as come within the scope of the appended claims;

Having thus described my invention, what I claim as new and desire to secure by Letters Patent is: I

1. A caster comprising an attachment plate having a recess formed. in its uppersurface; a'supporting yoke having avrecess formed inits under surface; a pintle separate from said plate and yoke projected into said recess in said plate and. provlded with a head adapted for seatlng inthe recess formed in said yoke, said pintle'being nonrotatable relatively'to said yoke, and adapt ed to rotate relatively to said plate'upon rotation of saidyoke relatively to said plate on saidpintle as an axis; ball bearings mounted in said plate recess and adapted for engaging the periphery of said pintle and the inner surface of said plate recess; and a washer permanently mounted on said pintie in engagement with said ball bearings and serving for retaining said ball hearings projected into the opening of said attachment plate loosely, the diameter of the opening in said attachment plate being slightly larger thanthediameter of the opening in said yoke;- a head mounted on said attachment member and engaging in the recess formed i'nsaid yoke for preventing relative rotation of said yoke and said attachment member; ball bearings positioned in said plate recess and engaging the periphery of said attachment member and the innersurface of said recess for aflording a bearing for rotation of said attachment member rela tivelyto said attachment plate; and means mounted on said attachment member for retaining said ball bearings in engagement with the base of said plate recess.

In testimony whereof, I have signed the i Vfo regomg specification.

r EDWARD A. HELLER. 

